IBM SG24-4817-00 User Manual
Page 203

This soft copy for use by IBM employees only.
is started it will display a line of information
in a box across the screen.
The UART type will be
presented in this display.
If you can locate the UART chip, it
′
s type can be determined
from the table below:
TYPE 1: 8250, 16450
TYPE 2: 16550, 16550A, 16550AF, 16550AFN
Type 1 UART
′
s only have single character buffer while the
Type 2 UART
′
s have a 16 character buffer.
The problem is
that Windows applications have trouble fetching characters
fast enough to prevent the next incoming character from
overwriting the single character buffer, resulting in
″
comm overrun
″
errors.
Sometimes running Windows in the
″
standard
″
mode will permit the configurator to work on a
Type 1 UART. To start Windows in the
″
standard
″
mode bring
it up by typing:
C:\win /s
Also, certain TSR
′
s, screen savers, and some video cards
can aggravate this problem.
This is a well documented
problem and much discussion can be found by searching the
world wide web for the keyword
″
UART
″ .
1.3.1
IBM DOS TCP/IP SLIP Connection Setup
IBM TCP/IP with CSD 2.1.1.4 MUST be already installed on the workstation.
This version or later of IBM TCP is required!
Use the TCP/IP CUSTOM
application to set and enable the COM# port as a SLIP interface with the
following configuration:
IP Address:
1.2.3.6
Destination Address:
1.2.3.5
Modem speed:
19200 bps
Port:
COM#
Note: # is the number of the COM port to be used.
Because communications may be over a SLIP connection, running with
Microsoft Windows, statements MUST be added to the SYSTEM.INI file
to prevent Windows from taking over the COM ports.
Add the following
3 statements to the •386Enh‘ stanza of SYSTEM.INI for each COM
COM port which is to be used by SLIP:
•386Enh‘
Com#AutoAssign=0
Com#Base=0
Com#Irq=-1
Note: # is the number of the COM port to be disabled.
AFTER YOU MAKE THESE CHANGES, YOU MUST RESTART WINDOWS!
************************************************************
Appendix D. Hints and Tips for the ATM 4-Port TR/Ethernet Bridge Module
187